Does technology such as virtual reality havea role in the treatment of pain?

Janet HOLLY, P.T.[1]

Online and print media have been praising virtual reality (VR) as the next generation of technology for treatment of a wide variety of health conditions including the treatment of pain.  However, is it worth all the hype? VR uses the alteration of multimodal stimuli to create an actual presence or immersion in a virtual world. (1) There is a wide range of possibilities for creating a VR experience ranging from MIRAGE illusion boxes, to low cost head-mount VR systems to fully immersive CAREN and CAVE VR laboratories.

Early researchers used the gaming aspect of VR as distraction therapy in the management of acute pain. The rationale proposed was that a patient attending to another sensory stimuli would perceive the noxious stimuli as lessened. (2) Research looking at cognitive distraction techniques during nociceptive inputs found that the PAG, perigenual ACC and orbitofrontal cortex increased in activity while the thalamus, insular cortex and midcingulate ACC decreased in activity. (3) Given the wide variety of sensory stimuli and change that can be obtained in a VR environment, early uses followed on the premise of sensory distraction.

Early adoption was found in the world of burn management. Patients using VR during burn debridement techniques were found to experience significantly less pain. (4) Originally, generalized gaming was used in this population and it was then expanded into the use of images of coolness with applications such as “Snow World” to create visual illusions of calm cool places during burn debridement with significant success. (5) VR applications are now clinically used in burn units to manage pain during painful procedures.

VR, as a distraction, was also looked at by Gold et al. for pain attenuation during painful medical procedures such as blood draws and IV placements for scans in children. They found out that the VR group as compared to the control groups had no significant changes in pain from start to completion of the painful procedures while the control groups which experienced greater pain. (6) (7) VR is also successfully being used to control pain and anxiety in painful dental procedures. (8)

After early successes using VR for acute pain, it was trialed for the treatment of chronic pain.  (9) Hoffman et al. demonstrated increases in range of motion in patients with chronic pain but no change in the base level of pain. In contrast, when VR was also trialed with patients with chronic neck pain an increase in range of motion and a decrease in neck pain was found. (10) Jones et al., used VR as an immersive visual imagery relaxation technique to achieve reductions in pain in a mixed chronic pain population. However, there was no long term follow up in either study but rather pre-post measures of pain. (11) (10) Given acute pain and chronic pain have different physiological processes, future studies in this area should therefore consider the neurophysiological variances of chronic pain to acute nociception.

Does the virtual reality world bring opportunities to address the body schema dysfunctions found in conditions such as CRPS and phantom limb pain? Embodiment in the virtual reality world has already demonstrated efficacy for the treatment of eating disorders, where the affected person has schematic misperceptions about body size. (12) Researchers determined that disturbed perceptions of body size in anorexia nervosa are plastic and can be positively altered. (12)

Several small pilot studies set out to explore its efficacy in CRPS.  Sato et al 2010 set out to improve arm function using VR. Markers were placed on the unaffected arm and the mirror image of the affected arm was seen on the virtual screen. They achieved a 50% reduction in pain and subjective reports of improved use of the upper extremity in four patients of five patients. A reduction in pain medication was seen in three of the five patients.  (13) In a similar study, Mouraux et al used 3D glasses and a Kinect™ camera to create a virtual mirror therapy session successfully reducing pain in a single session. (14) Another group of researchers took a different approach using an avatar that represented patients in the virtual world. Movement of the affected limb was amplified so that the avatar appeared to have greater movement than the patient. Patients were given a balloon popping tasks during the immersion session. Stereoscopic images, audio feedback and haptic feedback through floor vibration was used to enhance the virtual world to assist with the feeling of embodiment. (15) A different strategy was taken in using MIRAGE augmented virtual reality boxes to improve patient ownership of the affected limb. The patient places his hands in a box but sees an image of his own hands which are then digitally manipulated in real-time video. The hands appear in the same physical and spatial location, but the image is manipulated to appear larger or smaller.  (16) This randomized controlled trial reported improvements in ownership of the affected limb.  Finally, early findings of a large randomized control trial by Lewis et al., using the MIRAGE system and visual illusions in CRPS is demonstrating an ability to modulate pain in chronic CRPS. (17)

In 2016, Ortiz-Catalan et al., in a small trial of 14 patients, demonstrated reductions in phantom limb pain and improvements in ADLS and sleep which were maintained at 6 months post treatment. (18) This trial went beyond the use of visual sensory cues but rather used the phantom sensation to execute motor response of a phantom limb in a virtual world and as such embodiment of a limb while walking.

The literature around VR and pain is growing daily. However, much of it is limited to small sample sizes, lack of control groups, poor outcome measurement and lack of appropriate follow up. Opportunities abound to harness this multisensory world, in critically thought out trials, to address the various neurophysiological changes found in persistent and complex pain conditions. Exploring the technology first will allow clinicians to truly see the diverse array of possibilities rather then apply it solely to achieve an upscale version of an old treatment. It is likely that the greatest success will be found in program+ms that allow adjustments in VR programs to individuals’ neurophysiological contexts rather than a one size fits all model. However, this will bring large challenges in proving efficacy in trials.

References

1. Virtual reality and pain management: current treatment trends and future directions. Li, Angela, et al. 2, 2011, Pain Management, Vol. 1, pp. 147-157.

2. Distraction and coping with pain. McCaul, KD and Malott, JM. 1987, Psychology Bulletin, Vol. 95, pp. 516-533.

3. Distraction modulates connectivity of the cingulo-frontal cortex and the midbrain durin pain- an fMRI study. Valet, M, et al. 2004, Pain, Vol. 109, pp. 399-408.

4. Use of virtual reality for adjunctive treatment of adult burn pain during physical therapy: A controlled study. Hoffman, Hunter, Patterson, David R and Carrougher, Gretchen. 3, 2000, Clinical Journal of Pain, Vol. 16, pp. 244-250.

5. Pain control during wound care for combat related byrb unjuries using custom articulated arm mounted virtual reality goggles. Maani, C, et al. 2008, Journal of CyberTherapy and Rehabilitation, Vol. 1, pp. 193-198.

6. Virtual reality in out-patient phlebotomy: evaluating pediatric pain distraction during blood draw. Gold, JL, et al. 3, 2005, Journal of Pain, Vol. 6, p. S57.

7. Effectiveness of virtual reality for pediatric pain distraction during iv placement. Gold, JL, et al. 2, 2006, Cyberpsychology and Behaviour, Vol. 9, pp. 207-212.

8. The impact of virtual reality distraction on pain and anxiety during dental teratment in 4-6 year old children: a randomized controlled clinical trial. Aminabadi, Naswe Asl, et al. 4, 2012, Journal of Dental Research, Dental Clinics, Dental Prospects, Vol. 6, pp. 117-124.

9. Effectiveness of virtual reality=based pain control with multiple treatments. Hoffman, Hunter, et al. 3, 2001, Clinical Journal of Pain, Vol. 17, pp. 229-235.

10. Neck pain assessment in a virtual environment. Sarig-Bahat, H, Weiss, PL and Laufer, Y. 4, 2010, Spine, Vol. 35, pp. E105-E112.

11. The impact of virtual reality on chronic pain. Jones, TEd, Moore, Todd and Choo, James. 12, 2016, PLOS One, Vol. 11, p. e0167523.

12. A virtual reality full body illusion improves body image disturbance in anorexia nervosa. Keizer, Anouk, van Elburg, Anne-marie, Helms, Rossa and Dijkerman, Chris. 10, 2016, PLOS One, Vol. 11, p. e0163921.

13. Nonimmersive virtual reality mirror visual feedback therapy andits application for the treatment of complex regioanl pain syndrome: An open label pilot study. Sato, Kenji, et al. 2010, Pain Medicine, Vol. 11, pp. 622-629.

14. 3D augmented reality mirror visual feedback therapy applied to the treatment of persistent, unilateral upper extremity neuropathic pain: a preliminary study. Mouraux, Dominique, et al. 3, 2017, Journal of Manual and Manipulative Therapy, Vol. 25, pp. 137-143.

15. Two Virtual relaity pilot studies for the treatment of pediatric CRPS. Won, Andrea Stevenson, et al. 8, 2015, Pain Medicine, Vol. 16, pp. 1644-1647.

16. Changing appearance using visual illusions improves ownership of the painful hand in complex regional pain syndrome. Lewis, J, McCabe, C and Newport, R. Vienna, Austria : EFIC, 2015. European Pain Federation EFIC 2015.

17. Changing hand appearnace using visual illusion modulates hand pain in longstanding Complex regional pain syndrome. Lewis, JS, R, Newport and McCabe, C. Cork, Ireland : IASP, 2017. International Association for the Study of Pain CRPS Sig Scientific Meeting.

18. Phantom motor execution facilitated by machine learning and augmented reality as treatment for phantom lim pain: a single group, clinical trial inpatients with chronic intractable phantom limb pain. Ortiz-Catalan, MaxZepeda-Echavarria, Alejandra, et al. 10062, 2016, The Lancet, Vol. 388, pp. p2885-2894.

[1] Clinical Specialist in Pain Sciences, Senior Physiotherapist, Ottawa Hospital Rehabilitation Centre, Clinical Researcher Ottawa Hospital Research Institute ; 505, Smyth Road, Ottawa, Ontario, Canada e-mail: jhollypt@rogers.com  @innerchildca